Augmented reality is a technology that allows virtual imagery to be mixed with a real world physical environment. For example, an augmented reality system can be used to insert an image of a dinosaur into a user's view of a room so that the user sees a dinosaur walking in the room.
One of the harder problems to solve with augmented reality is the ability to overlay virtual objects on top of real objects. For example, it may be desired to mask a real object and make it appear as something else. Alternatively, it may be desired to add a new image into a scene that appears to be part of the scene, requiring the new image to block the view of all or a part of a real object in the scene.
Masking out real objects with virtual images can be complicated.